1. Field of the Invention
The present invention relates generally to a rotating apparatus, and in particularly, to a rotational positioning apparatus, which enables rotational positioning in both clockwise and counterclockwise directions.
2. Description of the Related Art
A variety of products are equipped with either a rotational positioning apparatus or rotating mechanism to satisfy different design requirements, modifications, and functionality or ease of operation. Therefore, rotational positioning apparatus or rotating mechanism are widely employed in non-electronic or electronic products such as DVD player, camera, toy, step machine, notebook computer, LCD monitor, PDA, digital video camera, or mobile phone, to provide technical solution directed to various requirements.
For electronic products, such as notebook computer, LCD monitor, PDA, digital video camera, or mobile phone, and the rotational positioning apparatus is usually employed to enable a display to be rotated horizontally with respect to a main body.
Referring to FIG. 9 for TW Publication No. 495130 titled “flat display device and rotating apparatus thereof” with disclosure of a rotating apparatus 130 being connected between a display panel 110 and a main body 120 of a notebook computer, thus the display panel 110 can be rotated with respect to the main body 120.
Also referring to FIG. 10, the rotating apparatus 130 is secured on the main body 120 (with reference to FIG. 9) via a fixed member 131, and attached to the display panel 110 via a rotating member 132. The fixed member 131 comprises a tube portion 139 having a through hole 133 defined therein, and two accommodating slots 134 are further defined longitudinally at two opposite ends on an inner wall of the through hole 133. The rotating member 132 comprises a cylinder portion 135 accommodated in the through hole 133 of the fixed member 131. Two locking slots 136 are defined axially at two opposite ends of an outer surface of the cylinder portion 135. Elastic members 137 are respectively engaged to the accommodating slots 134, wherein each of the elastic members 137 comprises an elongated extrusion 138. Thus, the display panel 110 is positioned by engaging the extrusions 138 to the locking slots 136 after the display panel 110 is rotated.
However, since the extrusions 138 and locking slots 136 are positioned by ragged-engagement, the extrusions 138 are usually not tightly engaged to the locking slots 136 due to error tolerance for manufacturing both, resulting the display panel to wobble in horizontal or vertical directions without stable position. Simultaneously, corresponding locations for the accommodating slots 134, extrusions 138 and locking slots 136 have to be precisely calculated if the extrusions 138 are to be inserted into the locking slots 136. In case of any one of the above three locations deviates, one extrusion 138 would be engaged in corresponding locking slot 136 while the other extrusion 138′ would be located outside the corresponding locking slot 136′, resulting inaccurate positioning as illustrated in FIG. 11.
Referring to FIG. 12 for TW Publication No. 551787 titled “electronic product incorporating rotating and positioning apparatus” with disclosure of another type of rotational positioning apparatus 200. The rotational positioning apparatus 200 comprises a rotating member 200, a positioning member 230, two elastic members 240, a fixed member 250 and a plurality of washers. A cylinder portion 222 is extended from a surface of the rotating member 220. The positioning member 230 is downwardly mounted on one side of the rotating member 220. A through hole is defined in a central portion of the fixed member 250 to accommodate the cylinder portion 222 of the rotating member 220, such that the rotating member 220 can rotate about the fixed member 250. The fixed member 250 has two shoulder portions 254 extending outwards from two opposite ends thereof, wherein each of the shoulder portion 254 is defined with a cutout 256 having an accommodating slot 258 at rear end thereof for accommodating the corresponding elastic member 240 therein. After the positioning member 230 is mounted on the rotating member 220, and the cylinder portion 222 of the rotating member 220 is engaged to the through hole 252 of the fixed member 250, the rotating member 220 can rotate about the fixed member 250, so as to stably position the rotating member 220 by locking the positioning members 230 into the elastic members 240 mounted at both ends of the fixed member 250.
However, the rotating member 220 of the above rotational positioning apparatus 200 can only rotate 180 degrees about the fixed member 250 at most, and the rotation at 180 degrees can only be made in one direction. Consequently, the rotating member 220 would fail in case of the rotating member 220 is required to rotate about the fixed member 250 beyond 180 degrees, or the rotating member 220 is required to rotate about the fixed member 250 in both clockwise and counterclockwise directions, dramatically limiting its application.
Also, according to the above rotational positioning apparatus, the slot is adopted as a position limiting apparatus and a positioning mechanism is implemented as a result of the positioning member interfering with the elastic member or spring with ball bearings. Furthermore, the rotating member and fixed member are usually made of zinc alloy which is soft and easily worn out. Thus, the components of the above rotational positioning apparatus are substantially worn out when they are subjected to friction at high frequency, leading to poor positioning mechanism.
As is understood above, the conventional rotational positioning apparatus are associated with many drawbacks such as one-direction-only rotation, limited rotation angle and poor positioning effect. In light of the problems above, it is an objective for the manufacturers to provide a rotational positioning apparatus capable of being rotated in both clockwise and counterclockwise directions, having flexible rotational angle, and being firmly positioned.